Yang, Dong. "Time, Symbol and Body: An Interpretation of the Theory of Causal Efficacy in Whitehead's Book Process and Reality." Beijing Normal University. 2007 

Abstract

Whitehead's theory of causal efficacy is based on the conception of time; Whitehead discussed the concept of time, and presented his new comprehension of time.  Whitehead's conception of time from Whitehead is neither the physical time of symmetrical-distributed, nor the internal feeling of time.  It's a conception of organic time.  In this way, time will change continuously from potentiality to the actuality.  Time is presented in the actuality, in the reality and in the space extension.  Whitehead proposed that time constituted the actuality and had the extensiveness of space.  Whitehead gave the definition of causal efficacy on the base the conception of organic time.  It was a starting point for understanding of the causal relation.

Whitehead used his new conception of time to define the causal relation.Whitehead argued that the ultimate causal relation is not originated from the impression, but from the history of the organic interaction.  The cause composes the result, the cause becomes the result, and it's not the serial relation of the two impressions.
            

The causal efficacy in the process is the focus of Whitehead's Metaphysics; it's the ultimate interpretation of the causal relation.  Whitehead's "causal efficacy" examined "the immediate presentation" (like Hume's concept of impression) and redefined "the symbol" (the modern scientific knowledge). Whitehead argued the causal efficacy a mode of perception of the elementary organism.
            

Whitehead regarded the causal efficacy as the ultimate dynamic power of his Metaphyics. Whitehead argued that the cosmos is a becoming process of the causal efficacy as the ultimate dynamic power.  Causal efficacy is not only the power, but also actuality.  This actuality can be perceived by the internal sensation.  For the perception of organism, causal efficacy is a mode of preception and a form of the perception ability.  Comparing the two modes of perception, whitehead argued that the causal efficacy is more basic and more primary than immediate presentation.
            

Body is the major place that the causal efficacy happens, the body was more general and abstract than general bodies, and furthermore it's a organic actual entity.  Body is the special form of organism.  This description of body gives the evidence that the time is the same as the space-extend.  Whitehead's argument emphasized the function of body in the sense of the organism environment.  He argued that body is the meeting-point of past and future, this theory is the major step of causal efficacy.
           

The picture of time and space basing on the causal efficacy got rid of the effect of the conception of time in modern philosophy.  It revived the metaphysics and made up another step for the development of metaphysics in its own history.  At the same time, we can feel the "cruel reality" of the causal efficacy.  This conception of time becomes a expression of the irresistable industry power and will be a new philosophical starting point.